Overwhelmed by spot fires in bone-dry pine needles and leaf litter at their feet, a Cal Fire captain and three firefighters retreated to a patch of bare earth on a Cobb Mountain ridgetop during the first hour of the voracious Valley fire on Sept. 12.

But they were not safe for long in the fenced goat pen where they took refuge. The wind picked up, the spot fires multiplied and one man saw the flames “sheeting and swirling” across a nearby driveway.

Then, a brush-covered slope “torched into a wall of flame,” according to Cal Fire’s first published report on the blaze that killed four people and charred 76,067 acres in Lake, Napa and Sonoma counties.

The flames “sent a significant wave of radiant heat” over the four members of the Boggs Mountain helitack crew at about 2 p.m., less than a half-hour after they had landed and set out to protect structures from a growing inferno. “They could feel their faces burning from the radiant heat,” said the report, which was posted Saturday on the blog wildfiretoday.com.

The four men ran to a fence, climbed over it and raced toward a steel garage on the property in the 15100 block of Bottle Rock Road near Cobb, deploying their portable fire shelters near the metal walls. The captain put out a mayday call over the radio.

In vivid detail, the report — called a green sheet — describes how one firefighter had to remove his gloves to tear the melted plastic covering away from the aluminum shell of his shelter. Another firefighter couldn’t get his shelter out of its case because the plastic cover had melted and fused to a white plastic protective sleeve.

He dropped it and ran to his colleague, and both men crouched under the first firefighter’s shelter.

The four men huddled together on the north side of the garage, “shielding the heat away from their already burned faces and hands,” the report says. “Each of them could see the visible burns to one another’s faces and hands.”

Capt. Pat Ward was the leader of the fire-besieged team described in the report, Janet Upton, a Cal Fire deputy director, said Saturday.

The three firefighters were identified as FF3, FF4 and FF5, and Upton confirmed they were Firefighters Niko Matteoli, Richard Reiff and Logan Pridmore, but she could not say which man was which.

The four were taken by helicopter to UC Davis Medical Center in Sacramento. Matteoli and Pridmore have been released and have returned to their homes, Upton said. Reiff is out of the hospital’s burn unit and is expected to be released soon, she said.

Ward remains in the burn unit, listed in critical condition but improving. “He has a long road to recovery ahead of him,” Upton said.

Matteoli, 23, of Santa Rosa comes from a line of Cal Fire firefighters in Sonoma County, including his great-grandfather, grandfather and grandmother. He started fighting fires five years ago and told a relative, while still in his hospital bed, that he was determined to continue his career.

On Saturday, the Valley fire was 97 percent contained with a crew of fewer than 400 working mostly on mop-up operations.

The report’s fire narrative says Ward repeatedly requested water bucket drops by their helicopter “to cool the atmosphere.” One firefighter attempted to drink from a hydration pack but found the water from the mouthpiece was “too hot to drink.”

Still crouched in their shelters next to the garage, the crew heard explosions coming from inside the structure, which had caught fire. The crew moved away, settling in a dirt driveway.

Another Cal Fire captain, positioned nearby, called for water drops on the crew’s position. But the helicopter, circling above, was unable to get near the men “due to the thick column of smoke convecting straight up into the atmosphere,” the report says.

A Cal Fire division chief, previously identified as Jim Wright, drove his pickup up a driveway off Bottle Rock Road and met up with a second team from the same helicopter as Ward’s team. Forced to turn back by heat and heavy smoke, he picked up the other team and headed back up the driveway, turning left at a fork.

“They could see the shiny aluminum of the fire shelters ahead of them,” the report says.

Ward and his crew were loaded into the pickup, with a firefighter holding shelters over the burned men to protect them from the heat as Wright drove to an emergency landing zone. The four injured men were flown to UC Davis.

Ward suffered second- and third-degree burns to his head, face, ears, neck, back, arms, hands, legs and feet. He has undergone several surgeries, the report says.

The three firefighters suffered first- and second-degree burns to the face, head, ears, arms and hands.

Upton said the green sheet, an internal document released Thursday within Cal Fire, is part of the agency’s “serious accident review process.” Compiled by a team of experts who surveyed the site, talked to witnesses and the injured firefighters, it is intended to convey the details of the incident to Cal Fire and other fire services.

“The idea is to get some important information out to the ranks while it’s fresh and we’re still experiencing the same (fire) conditions,” Upton said. Fire company officers are expected to discuss it with their crews at the station level, she said.

The fact-finding process will culminate in a report by a review board that will consider multiple factors and determine whether changes are needed in Cal Fire policy, training or equipment or whether the accident was “due to the inherent dangers of the job,” Upton said.

The green sheet does not draw any conclusions on the Valley fire incident, and Upton declined to comment on any specifics in the report.

But she said that Cal Fire officials, including 30-year wildland fire veterans, are talking about the low “fuel moisture” level after four years of drought in Lake County this year. Sixty percent levels are considered critical, and levels in Lake County’s brush have been in the high 40 percent range.

“We need a new adjective that’s worse than critical,” Upton said, adding that some Cal Fire veterans are describing the brush as “standing gasoline.”

Meanwhile, the fire season in October is at a historically dangerous peak, she said.

Some of California’s worst blazes — including the Oakland hills fire that killed 25 people in 1991 and the Cedar fire that covered 273,246 acres in San Diego County in 2003 — were in October.

You can reach Staff Writer Guy Kovner at 521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.

EDITOR'S NOTE: Four people were killed in the Valley fire. This story has been updated to remove an error in the number of deaths caused by the fire.